About 98% of iron ore is used to make steel – one of the greatest inventions and most useful materials ever created. While the other uses for iron ore and iron are only a very small amount of the consumption, they provide excellent examples of the ingenuity and the multitude of uses that man can create from our natural resources. Powdered iron: used in metallurgy products, magnets, high-frequency cores, auto parts, catalyst. Radioactive iron (iron 59): in medicine, tracer element in biochemical and metallurgical research. Iron blue: in paints, printing inks, plastics, cosmetics (eye shadow), artist colors, laundry blue, paper dyeing, fertilizer ingredient, baked enamel finishes for autos and appliances, industrial finishes. Black iron oxide: as pigment, in polishing compounds, metallurgy, medicine, magnetic inks, in ferrites for electronics industry. Major producers of iron ore include Australia, Brazil, China, Russia, and India.
Iron (Fe) is a metallic element and composes about 5% of the Earth’s crust. When pure it is a dark, silvery-gray metal. It is a very reactive element and oxidizes (rusts) very easily. The reds, oranges and yellows seen in some soils and on rocks are probably iron oxides. The inner core of the Earth is believed to be a solid iron-nickel alloy. Iron-nickel meteorites are believed to represent the earliest material formed at the beginning of the universe. Studies show that there is considerable iron in the stars and terrestrial planets: Mars, the “Red Planet,” is red due to the iron oxides in its crust.
Iron is one of the three naturally magnetic elements; the others are cobalt and nickel. Iron is the most magnetic of the three. The mineral magnetite (Fe3O4) is a naturally occurring metallic mineral that is occasionally found in sufficient quantities to be an ore of iron.
The principle ores of iron are Hematite, (70% iron) and Magnetite, (72 % iron). Taconite is a low-grade iron ore, containing up to 30% Magnetite and Hematite.
Hematite is iron oxide (Fe2O3). The amount of hematite needed in any deposit to make it profitable to mine must be in the tens of millions of tons. Hematite deposits are mostly sedimentary in origin, such as the banded iron formations (BIFs). BIFs consist of alternating layers of chert (a variety of the mineral quartz), hematite and magnetite. They are found throughout the world and are the most important iron ore in the world today. Their formation is not fully understood, though it is known that they formed by the chemical precipitation of iron from shallow seas about 1.8-1.6 billion years ago, during the Proterozoic Eon.
Taconite is a silica-rich iron ore that is considered to be a low-grade deposit. However, the iron-rich components of such deposits can be processed to produce a concentrate that is about 65% iron, which means that some of the most important iron ore deposits around the world were derived from taconite. Taconite is mined in the United States, Canada, and China.
Iron is essential to animal life and necessary for the health of plants. The human body is 0.006% iron, the majority of which is in the blood. Blood cells rich in iron carry oxygen from the lungs to all parts of the body. Lack of iron also lowers a person’s resistance to infection.
IRON ORE USES
|Name of iron compound||main components||properties||uses|
|Cast iron||iron + up to 5% carbon
Sometimes 1-3% silicon
engine cylinder blocks
|Galvanised iron||iron + zinc coating||resists rusting
motor vehicle bodies
|Steel||iron + less than 1% carbon||hard
cans & containers
|Stainless steel||iron +carbon, nickel,
motor vehicle parts
|Tool steel||iron +carbon, vanadium,
|metal cutting tools
THE PROPERTIES OF IRON
The chemical symbol for iron, Fe, comes from the Latin word for iron – ferrum. Iron is the second most abundant metal in the Earth’s crust (aluminium is the most abundant metal). The core of the Earth is solid iron, and iron is found in meteorites, but in the Earth’s crust iron is found mainly as minerals of iron oxide – hematite, magnetite, goethite and limonite. The mineral which is mostly used as ore for making iron is hematite. Its chemical formula is Fe2O3.
Iron is about 8 times heavier than water (its relative density is 7.87). When iron is exposed to the air it starts to turn back into iron oxide and the red powder that forms on the surface of iron is what we call rust. You may have seen rust on old cars or old iron sheds or roofs. To make iron stronger and less likely to rust it can be combined with carbon and other elements to make steel.
The mineral magnetite is very magnetic, and if you dangle a piece on a length of string it will orient itself north-south. Iron and some alloys of iron are also magnetic.
|The Properties of Iron|
|Mineral:||iron oxides: eg hematite and magnetite|
THE FORMATION OF IRON
Most deposits of iron ore in the world are found in rocks known as banded iron formations (BIFs). These are sedimentary rocks that have alternating layers of iron-rich minerals and a fine-grained silica rock called chert.
About 3000 million years ago there was no or very little oxygen dissolved in the oceans, because plants that produce oxygen had not yet evolved. However, the oceans did contain a lot of dissolved silica, which came from the weathering of rocks. Every now and again this silica precipitated out from the seawater as layers of silica jelly, which slowly hardened to become the rock we call chert.
Soluble iron oxide was also produced from the weathering of rocks and was washed into the sea by rivers. Some 2500 million years ago oxygen-producing life forms started to evolve and oxygen became part of the Earth’s atmosphere. In time some oxygen also dissolved in the seawater where it reacted with the soluble iron oxide to form insoluble iron oxide. This precipitated out of solution and on to the ocean floor as the minerals magnetite (Fe3O4) and hematite (Fe2O3).
Over many millions of years these processes of precipitating silica and iron oxide were repeated over and over again, and resulted in the deposition of alternating layers of chert (which is grey), hematite (which is red) and magnetite (which is black). Thus, the name banded iron formation comes from the characteristic colour banding of these huge deposits.
IRON IN INDIA
India is bestowed with large resources of Iron Ore. Iron ore occurs in different geological associations. However, in India, like in most other countries belonging to the Gondwana Super-continent, major economic deposits of Iron ore are found associated with volcano-sedimentary banded iron formation (BIF) of Precambrian age. The major iron ore deposits in India occur in Jharkhand, Chhattisgarh, Orissa, Karnataka, Goa, Maharashtra, Andhra Pradesh and Tamil Nadu. Most of India’s medium to high grade iron ore reserves is located at Madhya Pradesh, Goa, Orissa, Karnataka and Bihar.
India has large resources of good quality of Iron Ore. The in situ reserves estimated at about 18 billion tonnes. Haematite accounts for 12.3 billion tonnes, and magnetite is 5.4 billion tonnes. Besides, conditional reserves (haematite & magnetite) assessed as 5.5 billion tonnes. Estimation of resource takes into account +55% Fe for haematite. If grade below 55% Fe be consumed, resource position gets inflated. The major deposits of high-grade haematite occur in Madhya Pradesh (estimated reserves: 630 Mt), Orissa (320 Mt), Karnataka (220 Mt) and Bihar (85 Mt). Medium grade reserves (62-65% Fe) are found in Bihar (1,790 Mt), Orissa (1,300 Mt), Madhya Pradesh including Chhattisgarh (485 Mt), Karnataka (440 Mt) and Goa (150 Mt). Metallurgical-grade magnetite ore is found in Karnataka (1,150 Mt), Goa (100 Mt) and Andhra Pradesh (40 Mt).
While Hematite reserves are mostly confined to the state of Bihar, Orissa, MP, Karnataka and Goa, the bulk of Magnetite ore is available in Karnataka State and to some extent in Andhra Pradesh and Goa. Haematite Ore represents 75% of the resources. More than 50% of Haematite ore are of medium to high grade having Fe content 62% & above .
Major deposits of Haematite iron ore in India are located in the following main regions :
Zone A : Orissa – Bihar (Bonai Konjhar)
Zone B : Madhya Pradesh
Zone C : Karnataka (Bellary – Hospet)
Zone D : Goa – Redi
Zone E : Karnataka (Magnetite Deposit)
Major iron ore ranges occurring in these areas are given as below:
Orissa – Bihar:
i) Barsua-Kalta range
(ii) Bolani range
iii) Kiriburu – Meghahataburu range
iv) Takhurani range
v) Naomandi – Katamati range
vi) Chiria – Budhaburn group
vii) Joda group
viii) South Banspani group
ix) Malangtoli block
ii) Rowghat range
iii) Malamaya – Aridougri group
iv) Bailadila range
v) Katni – Jabalpur area
i) Surjegarh range
ii) Redi group
i) Donimalai range
ii) Kumaraswami range
iii) Ramandurg range
iv) NEB range
v) Thimmappannagudi range
vi) Ettinahatti range
vii) Kemmangundi deposit
i) Goa deposits
Major deposits of magnetite ore in under table:
|Karnataka|| • Bababudan range
• Kudremukh deposit
|Tamilnadu|| • Kanjamalai deposit
• Thiruvannamalai deposit
|Andhra Pradesh||• Ongole deposit|
|Goa||• Goa deposit|
|Himachal Pradesh||• Mandi deposit|
Recoverable Reserve of Hematite
(Unit: in million tones)
|State||High Grade (Fe+65%)||Medium Grade (Fe-62-65%)||Low Grade( Fe below 62%||Unclassified||Others||Blue Dust Black Iron||Total|
Recoverable Reserve of Magnetite
(Unit: in million tones)
|State||Metallurgical Grade||Coal Washery Grade||Foundry||Unclassified||Others||Total|
Out of 225 mines, 34 are owned by public sector undertakings, which produce 55 per cent of the total production. Of this, 11 mines have the capacity to produce more than one million tones per annum and contribute about 48 per cent of the total output. Private sector also has large mines of which six have annual production capacity exceeding one million tones. These six mines contribute about 16 per cent to the national production. Public sector enterprises like the National Mineral Development Corporation, Kudremukh Iron Ore Company, Steel Authority of India Limited and Orissa Mining Corporation dominate the iron ore sector.
National Mineral Development Corporation: Incorporated in 1958 as a fully Government of India owned public enterprise with the objective of developing all minerals other than coal, petroleum and atomic minerals, NMDC is involved in the exploration of wide range of minerals including iron ore, copper, rock phosphate, lime stone, dolomite, gypsum, bentonite, magnesite, diamond, tin, tungsten, graphite, beach sands etc.
Production of Iron Ore:
The present production of iron ore is 16.97 million tons, from 3 fully mechanised mines viz., Bailadila Deposit-14/11C, Bailadila Deposit-5, and Donimalai Iron Ore Mines.
• Bailadila Deposit-14(Madhya Pradesh): The mine was commissioned in 1968, the original reserves of this mine were 101 Mn tones of +66% Fe grade. The present reserves are16.72 Mn tones. The production capacity 5.50 million tones ROM (Run of Mine) ore per annum.
• Bailadila Deposit-11/C: To supplement production of Bailadila-14 mine, NMDC has commissioned in June 1988 a new mine at Deposit-11C, with a reserve of 131 million tones close to Bailadila-14. The mineable reserves as on April, 2003 are 72.56 million tones. The mine has been developed to produce 5.0 million tones of ROM ore per annum.
• Bailadila Deposit-5: Original reserve of this mine was 240 million tones and present Reserve of 68.30 million tones. The production capacity is 6 million tonnes of ROM ore per annum.
• Donimalai Iron Ore Mine: Located in Karnataka Original reserves of this mine were 108 million tones and present Reserve of 37 million tones. The production capacity 4 million tones of ROM ore per annum.
Production of Iron ore by NMDC in the year 2003-04 stood at 18.15 million tons. Exports of the ore were 7.24 million tones
Kudremukh Iron Ore Company: a wholly owned Government of India Enterprise was established in 1976, designed to produce 22.6 million ton’s of crude ore per year with a daily production capacity of ROM 100,000 tones. The major exporting partners are China, Taiwan, Japan and Iran.
This company is into processing of ore and also into the manufacturing of steel through subsidiary.
Steel Authority of India: A public sector undertaking , SAIL is a fully integrated iron and steel maker, producing both basic and special steels for domestic construction, engineering, power, railway, automotive and defence industries and for sale in export markets. SAIL has five iron ore mines at Meghahatuburu, Kiriburu, Bolani, Barsua and Kalta and four limestone/dolomite quarries at Kuteshwar, Purnapani, Bhawanathpur and Tulsidamar. Iron ore is extracted through open cast mining method. Most of the mines are mechanised with washing facility. The iron content of ore from these mines currently ranges from 62% to 65%. While lump ore is used directly into blast fumaces, the fines ore is first agglomerated in the sinter plant and then fed into the blast furnaces.
Production of iron ore in the year ending March 2004 was 12.78 Mn ton. The total turnover of the company was an all-time high of Rs. 24,178 crore during 2003-04, a growth of 26 per cent as compared to 2002-03. SAIL also recorded the highest-ever net profit of Rs. 2,512 crore. Sail has 26% market share.
Tata Iron and Steel Company (TISCO): a private sector undertaking, Tata steel is an integrated player in Iron steel market, one of the oldest establishments, it has its iron ore and chrome mines in Orissa. Tata Steel operates highly mechanised Iron ore mines at Noamundi and Joda for meeting its Steelworks requirements. The surplus quantity of lumps and fines are exported to steel mills across the globe.
The company is also studying the possibility of developing virgin deposits to augment its production.
Sesa Goa Ltd. is a major exporter of iron ore having its mining operations in Goa, Karnataka and Orissa. The sales of iron ore in the year 2003-04 was 8.5 Mn ton.
Jindal Steel and Power Ltd.: Jindal Steel & Power Limited (JSPL) is an OP Jindal group company having its corporate office at New Delhi and production facilities at Raigarh and Raipur, both in the state of Chattisgarh. Raigarh, the principal production facility of the company has is rotary kilns with a combined capacity of 6,50,000 tones per annum; making it the largest coal-based sponge iron manufacturing capability in the world. JSPL has entered into technical services assistance agreement with JFE (earlier known as NKK Corporation), Japan for technology transfer.
JSPL has a captive iron ore mine at Orissa with total reserves estimated to be about 10 million MT, out of which about 4 million MT have been extracted. The mine is currently producing about 0.6 million MT of sponge grade ore and has been developed with the latest, fully mechanized techniques.
Essel Mining and Industries Ltd.: This is an Aditya Birla Group company with two divisions Mining division and Ferro chem. Division. The company is head quartered in Kolkata and has its mining operations in the Berbil area of Keonjhar district in the state of Orissa. The mining division was established in 1970 and is today one of India’s largest companies in Iron Ore Mining, Processing, Research and Trade in the non-captive private sector.
Its total reserve is estimated at 125 Million Tones of high quality +65% Fe content ore.
Orissa Mining Corporation: The Orissa Mining Corporation Limited (OMC) was jointly established by the Union and State Government in the first decade of the country’s independence. It was the first public sector undertaking in Orissa. By 1962, OMC became wholly state owned enterprise.
OMC possesses a reserve of 900 million tones (mt) of iron ore, 19 mt of manganese ore, 28 mt of chromite, 730 mt of bauxite, 19 mt of limestone and other minerals. The Daitari Iron Ore Mine is the flagship of OMC’s operations. The production capacity of the mine is 2 million tonnes of iron ore annually to produce washed lumps calliberated ore and fines. Most of this is being exported through Paradip port to different countries viz China, Japan, Malaysia, Pakistan and Romania.